From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753163AbaC3Xlq (ORCPT ); Sun, 30 Mar 2014 19:41:46 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:36426 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753061AbaC3XZC (ORCPT ); Sun, 30 Mar 2014 19:25:02 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Sarah Sharp" , "Bjorn Helgaas" , "Chris Cheng" Date: Mon, 31 Mar 2014 00:23:35 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 118/200] PCI: Enable INTx if BIOS left them disabled In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.249 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.56-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Bjorn Helgaas commit 1f42db786b14a31bf807fc41ee5583a00c08fcb1 upstream. Some firmware leaves the Interrupt Disable bit set even if the device uses INTx interrupts. Clear Interrupt Disable so we get those interrupts. Based on the report mentioned below, if the user selects the "EHCI only" option in the Intel Baytrail BIOS, the EHCI device is handed off to the OS with the PCI_COMMAND_INTX_DISABLE bit set. Link: http://lkml.kernel.org/r/20140114181721.GC12126@xanatos Link: https://bugzilla.kernel.org/show_bug.cgi?id=70601 Reported-by: Chris Cheng Reported-and-tested-by: Jamie Chen Signed-off-by: Bjorn Helgaas CC: Sarah Sharp Signed-off-by: Ben Hutchings --- drivers/pci/pci.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1078,6 +1078,8 @@ EXPORT_SYMBOL_GPL(pci_load_and_free_save static int do_pci_enable_device(struct pci_dev *dev, int bars) { int err; + u16 cmd; + u8 pin; err = pci_set_power_state(dev, PCI_D0); if (err < 0 && err != -EIO) @@ -1087,6 +1089,14 @@ static int do_pci_enable_device(struct p return err; pci_fixup_device(pci_fixup_enable, dev); + pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin); + if (pin) { + pci_read_config_word(dev, PCI_COMMAND, &cmd); + if (cmd & PCI_COMMAND_INTX_DISABLE) + pci_write_config_word(dev, PCI_COMMAND, + cmd & ~PCI_COMMAND_INTX_DISABLE); + } + return 0; }